On page 660 of their superb article – “Services Trade and Policy” – in the September 2010 issue of the Journal of Economic Literature, Joseph Francois and Bernard Hoekman include a graph (from a 2009 working paper by Batshur Gootiiz and Aaditya Mattoo) showing that countries with less-restrictive services-trade policies generally have higher per-capita incomes than do countries with more-restrictive services-trade policies.
No surprise there.
An earlier, ungated version Francois’s and Hoekman’s informative paper is here. See Fig. 4.1 on page 67.